data_global _chemical_name_mineral 'Natrosilite' loop_ _publ_author_name 'Pant A K' _journal_name_full 'Acta Crystallographica, Section B' _journal_volume 24 _journal_year 1968 _journal_page_first 1077 _journal_page_last 1083 _publ_section_title ; A reconsideration of the crystal structure of beta-Na2Si2O5 ; _database_code_amcsd 0009344 _chemical_formula_sum 'Na2 Si2 O5' _cell_length_a 12.329 _cell_length_b 4.848 _cell_length_c 8.133 _cell_angle_alpha 90 _cell_angle_beta 104.24 _cell_angle_gamma 90 _cell_volume 471.181 _exptl_crystal_density_diffrn 2.568 _symmetry_space_group_name_H-M 'P 1 21/a 1' loop_ _space_group_symop_operation_xyz 'x,y,z' '1/2+x,1/2-y,z' '1/2-x,1/2+y,-z' '-x,-y,-z' loop_ _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z Na1 0.44362 0.75331 0.37932 Na2 0.47262 0.22518 0.13722 Si1 0.18240 0.18422 0.02770 Si2 0.27681 0.29480 0.40291 O1 0.21462 -0.14126 0.01551 O2 0.26717 0.62025 0.45371 O3 0.18097 0.24614 0.22574 O4 0.40078 0.23205 0.39106 O5 0.06384 0.24500 -0.09331 loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 Na1 0.01630 0.01180 0.01100 -0.00080 0.00110 0.00010 Na2 0.01290 0.01190 0.01510 0.00020 0.00490 0.00090 Si1 0.00650 0.00460 0.00570 0.00020 0.00110 -0.00020 Si2 0.00810 0.00410 0.00480 0.00020 0.00150 -0.00070 O1 0.01080 0.00580 0.01520 0.00210 0.00560 -0.00080 O2 0.01610 0.00600 0.00910 -0.00040 0.00570 -0.00240 O3 0.01030 0.01370 0.00620 -0.00010 0.00080 -0.00210 O4 0.00470 0.00570 0.00560 0.00080 0.00210 -0.00070 O5 0.01090 0.01120 0.00770 0.00100 0.00080 0.00090